powershellpowershell-ise

Passing a variable to a powershell script via command line

I am new to powershell, and trying to teach myself the basics. I need to write a ps script to parse a file, which has not been too difficult.

Now I want to change it to pass a variable to the script. that variable will be the parsing string. Now, the variable will always be 1 word, and not a set of words or multiple words.

This seems uber simple yet is posing a problem for me. Here is my simple code:

$a = Read-Host
Write-Host $a

When I run the script from my command line the variable passing doesn't work:

.\test.ps1 hello
.\test.ps1 "hello"
.\test.ps1 -a "hello"
.\test.ps1 -a hello
.\test.ps1 -File "hello"

As you can see, I have tried many methos with no success, of the script taking the value an outputting it.

The script does run, and waits for me to type a value, and when I do, it echos that value.

I just want it to output my passed in value, what minuscule thing am I missing?

Thank you.

Solution

  • Here's a good tutorial on Powershell params:

    PowerShell ABC's - P is for Parameters

    Basically, you should use a param statement on the first line of the script

    param([type]$p1 = , [type]$p2 = , ...)

    or use the $args built-in variable, which is auto-populated with all of the args.